Various devices have been heretofore provided to prevent forced entry through a door, such as by breaking the lock of the door or the door frame in the area of the striker plate. Such devices usually comprise securing a metal plate on the door where the locks are installed. Another improvement has been to make the door keepers much stronger. However, when these keepers are installed within the door frame it is necessary to install them close to an outer edge of the frame where the door is received, and this weakens the frame in the outer edge area adjacent the lock striker. When a burglar breaks the door by forced entry, it is usually the frame that breaks in the area of the lock striker.